Governing mechanism for prime movers



March 8 1927.

W. L. R. EMMET GOVEENING MECHANISM FOR PRIME MOVERS Filed May s. 192s df mw @mi Imm A. J, M mf/r rm Q M non. A @L ffm H ,M ,W/ y In CIIPatented Mar. 8, 1927.

UNITED STATS 1,620,527 PATENT DFFICE.

'WILLIAM L. R. EMMT, OF SCHENCTADY, NEW YORK, ASSIGNOR T0 GENERAL ELEC-TRIO COMPANY, A COREORA'ION OF NEW YORK.

GOVERNING MECHANISM FOR. PRIME MOVERS.

Application filed May 8,

The present invention relates to speed governing mechanisms for primemovers such as elastic fluid turbines and the like, and has for itsobject to provide an improved apparatus of this character which issimple in structure` reliable in operation, readily manufactured at alow cost, and capable of maintaining close regulation.

For a consideration of what I believe to be novel and my invention,attention is directed to the accompanying description and the claimsappended thereto.

In the drawing, the figure is a diagrammatic view ot' an elastic fluidturbine provided with a governing mechanism embodying` my invention.

According to the preferred form of my invention, I provide in connectionwith a prime mover a valve means which controls the admission of elasticfluid thereto which valve means is biased toward closed position by aspring or other suitable means and for operating the valve means Iprovide a suitable motor for opening it against the force of the biasingmeans and speed responsive mechanism which at definitely periodicintervals effects operation of the motor to cause it to give the valve apush toward open position, the valve being thereby opened by asuccession of impulses. By definitely periodic intervals of' time I meansuccessive intervals of time ot definite or appreciable length. Undersome conditions the definitely periodic intervals will be of equalduration. With changing conditions the intervals will not be of equal.duration but they will always be of a definitely periodic nature. Thearrangement `is such that when the speed decreases beyond the desiredvalue the motor is operated to move the valve means toward open positionand this movement continues until the speed reaches a value a certainamount higher than the desired value when the motor is caused to ceaseoperation and the valve is permitted to move toward closed positionunder the iniiuence of the biasing force.

It then continues to move toward closed position until the speed againfalls below the desired value when the speed responsive mechanism oncemore comes into operation to cause the motor to move the valve towardopen position. Preferably the motor is controlled by opening and closingan electric circuit, the contacts i'or doing this being controlled by asuitable speed governor. The

arrangement may be such that when the circuit is closed the motor isoperated to effect opening of the valve means while when the circuit isinterrupted by the speed responsive device or governor the operation ofthe motor is interrupted and the valve means permitted to move towardclosed position. Means are provided to insure a definite change in speedbetween the opening and closing of the contacts so that the contactswill be definitely separated and closed, and for this purpose Ipreferably provide a holding magnet in the circuit which acts to holdthe contacts closed until there has been a" definite speed change. Thisholding magnet is deenergized as soon as the circuit is broken,whereupon the contacts are definitely separated, and is energized assoon as the i circuit is closed again to definitely close the contacts.Also to render the governor nonisochronous, I preferably provide meansby which movement of the valve means causes change of the speed at whichcontact is made and broken whereby there is provided a definite speedrange between no load and full load. By suitable adjustments andproportioningv of the parts the speed range may be made such as to givestable operation of the governing mechanism. The motor for moving thevalve means toward open position may with advantage be a fluid-actuatedmotor comprising a cylinder, a piston therein connected directly to thevalve means and a pilot valve for controlling the admission ot actuatingfluid to and its discharge from the cylinder, the pilot valve beingarranged to have two positions, one in which it admits' actuating fluid'to the cylinder and another in which it cuts oit the actuating fluidsupply and permits escape of the actuating fluid from the cylinder. Thepilot valve is then actuated by an electromagnet in the circuitcontrolled by'fthe contacts. By this arrangement but asmall current isrequired in the central circuit which simplifies the matter of openingand closing the circuit.

It will be seen that by my invention the valve means controlling theadmission of elastic iiuid to the prime mover is opened and held open toany desired degree by a succession of impulses and releases.v Theperiodicity with which the mechanism acts is readily controlled andregulated by proportioning the parts and providing suitable means fordampening or retarding the Inovements, the arrangement being such thatthe speed variations between interruptions of the electrical circuit isso small as to be unobj ectionable.

Referring to the drawing, 5 indicates an elastic fluid turbine providedwith a conduit 6 for the admission of elastic fluid. The shaft of theturbine is indicated at 7 and the high pressure packing at 8. Only thehigh pressure or admission end of the turbine is illustrated as thedetails of structure of the turbine form no 'partof the presentinvention. The turbine indicated is to be 4taken as typical of anysuitable turbine or other prime mover. i

According to my invention, I provide in the admission conduit 6 a valve10 for regulating t-he flow of elastic Huid to the turbine which valveis so arranged that it is always urged or biased toward closed position.For example, it may have its stem 11 connected to a piston 12 located ina cylinder 13 and acted upon by a spring 14 which serves always to forcethe valve toward closed position. The valve is adapted to be openedagainst the action of spring 14 by fluid pressure admitted to cylinder13 through an opening 15. Connected to cylinder 13 is a valve casing 16in which are located two sets of valves 17 and 18 carried by a stem 19and arranged to open and close ports 20 and 21 in valve casing 16.Valves 17 control the flow of actuating Huid from a supply conduit 22through ports 20 to the opening 15 in cylinder 16 and valves 18 controlthe flow of actuating fluid from cylinder 13 through opening 15 andports 21 to a discharge conduit 23. The arrangement is such that whenvalves 17 are open valves 18 are closed and when valves 18 are openvalves 17 are closed. Casing 16 and valves 17 and 18 form in substance areversible pilot valve of a fluidactuated motor comprising piston 12 andcylinder 13.

In connection with the foregoing arrangement I provide means responsiveto the speed of the prime mover for periodically reversing the positionsof valves 17 and 18, which means that actuating' iiuid is being eitheradmitted to cylinder 13 through opening 15 to move valve 10 toward openposition or is being permitted to escape from cylinder 13 throughopening 15 to permitspring 14 to move valve 10 toward closed position,thereby giving to valve 10 deiinitely periodic impulses. To this end,according to the embodiment of my invention illustrated in the drawing,I connect the end of stem 19 to an armature 24 which moves between theends of the poles of an electromagnet 25 and suitable iiXed stops 26,the armature beine' biased toward the stops by a spring 27. rIlliewinding of electromagnet 25 is connected into an electric circuitincluding a suitable source of potential 28,

a holding magnet 29, a fixed contact and a movable contact 31, thecircuit wires being indicated at 32. Holding magnet 29 and fixed contact30 are mounted on a stationary arm 33 car ied by a housing` MovableContact 31 is mounted on a `lever arm 35 pivoted on a bracket on housing34 and carrying at one end an armature 37 which cooperates with holdingmagnet 29. Connected to the end of turbine shaft 7 is a speed governorwhich acts on. lever arm It comprises a rod 38 iixed to shaft 7 andprovided with a liXed collar 39' at its inner end and an axiallyadjustable nut 40 at its outer end. On nut 40 is a 'flange 41. Mountedon nut 40 to slide axially thereon is a flanged ring 42 which isconnected to hxed collar 39 by leaf springs which carry the governorweights 44. Arranged between collar 39 and ring 42 is a spring 45 whichacts to force ring l2 against flange 41 and oppose its movement by thegovernor weights. On the end ot rod 38 is an axiallyv extending pin 46on which slides a block 46a which follows the movements of ring 42. Inblock 46aL is a bearing in which rests one end of a bearing pin 47 theother end ot which rests in a bea-ring 48 on lever arm 85. The action ofspring 45 is opposed by a spring 49 connected at one end to lever' arm35 and at the other end to an arm 50 pivoted at 51 on casing 16. Spring49 is held under tension by arm and when the end ot lever arm 50 movesaway from lever arm the tension of the spring 49 is increased, whilewhen it is moved in the other direction, the tension is decreased. Arm50 is pivotall)Y connected to stem 11 of valve 10 by a link 52 and lever53. Spring 45 can be adjusted by means of nut 40 and spring 49 can beadjusted through its connection with lever arm 50.

In use the governor springs 45 and 49 are adjusted relatively to eachother for the desired turbine speed. lllhen this desired 'turbine speedis exceeded governor weights 44 move outwardly against the action ofspring 45 and at a certain predetermined speed spring 49 will becomeeHect-ive to turn lever arm and move contact 31 awayfrom contact 30,thus opening the` circuit through electromagnet rfhis deenergizeselectromagnet 25 and permits spring 27 to reverse the position of valves17 and 18. the former being closed to shut oil'l the flow of actuatingfluid to cylinder 13 and the latter opened to permit actuating fluid toescape therefrom. is soon as this occurs spring 14 begins to move valve10 toward closed position to decrease the amount of elastic fluidadmitted to the turbine. rllhe speed of the turbine will then begin todecrease and when it reaches a certain lower value, spring 45` of thespeed governor will move lever 35 to again bring movable Contact 31 intoengagement with tixed contact thereby closing the circuit ofelectromagnet 25. Upon being reenergized, electromagnet 25 will drawarmature 2l awayl from stops 26 back against its pole pieces therebyreversing the posit-ion of valves 17 and 18 once more, opening theformer and closing the latter. Motive luid will then be admitted tocylinder 13 to move valve 10 toward o en position and thus increase thesupply o elastic fluid admitted to the turbine. This causes the turbineto again increase in speed and when the speed aga-in reaches thepredetermined higher' value the cycle of operation just described willbe repeated. The holding magnet 29 is of such strength that there mustbe a certain definite change in speed before the imbalance betweensprings and 49 becomes great enough for spring 49 to move lever 35 toseparate contacts 3() and 31. As soon as they separate, however, holdingmagnet 29 is deenergized so it exerts no pulling force on the leveruntil the circuit is again closed by contacts 30 and 31. The valve 10 isthus opened by a succession of impulses. The time periods of theimpulses are regulated by dampening the movements of the apparatus insuch a manner that the functions ot governing are accomplished as fastas necessary Without giving an inconveniently rapid succession ofcontacts and impulses. This dampening action may be obt-ained readily bythe design of the parts of the apparatus itself or by other suitablemeans.` The flow of the oil to and from cylinder 13 through the portshas a dampening ciiect and by making the ports of suitable size thedesired dampening eiiiect is readily obtained. rlhis dampening eiiect iscaused, as will be readily understood, by the resistance offered to theflow of oil through the ports. also the proportion and spacings; aresuch that the speed variation between interruptions of the electricalcircuit is so small as to be unobjectionable.

To insure stable governing it is desirable that a governing mechanism benon-isochronous, that is, that the full load speed be lower than the noload speed and in the present instance I accomplish this by adjustingthe tension of spring 49 with changes in load, the arrangement beingsuch that as the load increases the tension of the spring t9 increasedwhich means that the mechanism will operate to separate contacts 30, 31at a lower speed. Any suitable means may be used for adjusting spring19, that shown comprising the lever arm 50, link 52, and lever arm 53.With this arrangement it will be seen that as valve 10 opens lever 53 isturned on its pivot to push arm 50 toward the right thereby increasingthe tension on spring 49. The tension increases as valve 10 opens andthe arrangement and proportioning of the parts is such that the desiredchange in speed between no load and full load is obtained.

A construction embodying my invention has the advantage that practicallyno load is imposed on the speed governor, it being called upon merely tomalte and break an electric circuit. es a result it may be small andvery simple in structure so it can be made at a low cost, but at thesame time be very sensitive. The amount of current required to operatethe apparatus will be small and since a definite break and make ot' thecontacts is insured by the holding magnet 29 no diii'iculty isexperienced with burning or wearing ot' the contacts. 10 is operated bysuccessive pushes it will be kept continuously in motion, moving lirsttoward open position and then toward closed position so it has noopportunity to become stuck in any position and since it is biasedtoward closed position it will always close in case the supply ofactuating fiuid to cylin der 13 tails. I may with advantage utilize asactuating Huid, fluid taken from the force feed lubricating system forthe turbine so that in case the lubricating pressure ,for the nachine.fails. control valve 10 will close.

The type of speed governor illustrated is shown only by way ot exampleand it will 'be understood that any suitable means responsive to thespeed ot the machine may be used.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation ol' my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

`What I claim as new and desire to secure by Letters Patent ot theUnited States, is:

1. In combination, a prime mover, a valve controlling the admission ot'elastic Huid thereto, means which biases said valve toward closedposition, a motor for opening` the valve against the action oi' saidbiasing means, a reversible controlling means ttor said motor, and meansresponsive to the speed ot the prime mover for periodically reversingsaid controlling means, whereby the valve at all times is being movedeither toward closed position under the influence ot said biasing meansor toward open position by said motor.v

` Q. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, means which biases said valve toward closedposition` a fluid-actuated motor for opening the valve against theaction oi said biasing means, a reversible valve means for the motorwhich in one position etl'ects movement of the motor to open the valveand in the other position permits thev Since valve valve to closeunderthe influence of said biasing means, and means responsive to the speedofl the prime mover for periodically reversing said valve means.

3. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, means Which biases said valve toward closedposition, a fluidactiiated motci' for opening the valve against theaction of said biasing means, a reversible valve means for the motorwhich in one position effects movement of the motor to open the valveand in the other position permitting the valve to close under theinfluence of said biasing means, an electromagnet for moving said valvemeans, an electric circuit for the electromagnet, controlling means insaid circuit, and means responsive to the speed of the prime mover forperiodically opening and closing` said circuit-controlling means.

4l. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, means which biases said valve` toward closedposition, a fluid-actuated motor for opening the valve against theaction of said biasing means, a reversible valve means for the motorwhich in one position effects movement of the motor to open the valveand inthe other position permits the valve to close under the influenceof said biasing means, an electromagnet for moving said valve means, anelectric circuit for the electromagnet, separable contacts in saidcircuit, and means responsive to the speed of the prime mover forperiodically opening and closing said contacts.

5. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, a. fluid-actuated motor for the valve, meansbiasing the motor to a position Wherein the said valve is closed, apilot valve for the motor Which has tvvo positions, one iii which themotor 'is caused to niove to open the first-named valve and the other inwhich the motoi is permitted to move under the influence of said biasingmeans to close the first-named valve, electrically-operated means foreffecting movement of' the pilot valve from one position to the other,an electric circuit in which it is included, separable contacts in saidcircuit, a lever to which one of' said contacts in connected, and meansresponsive to the speed of' the prime mover for moving said leverperiodically to open and close said contacts.

(i. In combination, a prime move". a valve controllingI the admissionof' elastic fluid thereto, a fluid-actuated motor for the valve, meansbiasing the motor to a position Wherein the valve is closed, a pilotvalve for the motor which has two positions, one in Which the motor iscaused to move to open the first-named valve and the other in Which themotor is permitted to move under the influence of said biasing means toclose the first-named valve, electrically-operated means for effectingmovement of the pilot valve from one position to the other, :an electriccircuit in Which it is included, sep'- arable contacts in said circuit,a lever to which one of said contacts is connected, means responsive tothe speed of the prime mover for moving said lever to open and closesaid contacts. and a holding magnet in sind circuit for said lever.

7. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, means which biases said valveto closed position,a motor for opening the valve against the force of the biasing means,and means controlled by the speed of theV prime mover for periodicallysuppl-ying actuating medium to said motor.

S. In combination, a prime mover, a valve controlling the admission of'elastic fluid thereto, means Which biases said valve to closed position,a motor for opening the valve against the force of the biasing means,means controlled by the speed of the prime mover for periodicallysupplying actuating medium to said motor, and means for rendering tliegoverning action non-isochronous.

9. In combination, a prime mover, a valve `controlling` the admission ofelastic fluid thereto, means Which biases said valve to closed position,a motor for opening the valve against the force of' the biasing means,an electric circuit controlling the supply of actuating medium to saidmotor, and means responsive to the speed of' the prime mover for openingand closing said circuit at denitely periodic intervals of time.

l0. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, means which biases said valve to closed position,a motor for opening the valve against the force of the biasing means. anelectric circuit controlling the supply of actuating medium to saidmotor, means responsive to the speed of the prime mover for opening andclosing said circuitat def`initcly periodic intervals, and means forrendering the governing' action non-isochronous.

l1. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, means which biases said valve to closed position,a Huid-actuated motor for opening the valve against the force of saidbiasing means, a pilot valve controlling the admission of motive fluidto and from the motor, an electric circuit including means for operatingthe pilot valve, a speed governor for periodically opening and closingsaid circuit, and means for automatically setting said governor inaccordance with the opening of the controlling valve for the prime moverso as to render the governing action non-isochronousl2. In combination,a prime mover, a valve controlling the admission of elastic fluidthereto, a motor for moving the valve, means including an electriccircuit for effecting movements oi said valve, means re sponsive to thespeed of the prime mover for interrupting' said circuit, and a holdingmagnet in said circuit which serves to prevent interruption of thecircuit until a predetermined cliange in speed has taken place.

13. In combination, a prime mover, a valve controlling the admission ofelastic fluid thereto, a motor for moving the valve, means including anelectric circuit for effecting movements of said valve, means responsiveto the speed of 'the prime mover for interrupting said circuit, aholding magnet in said circuit which serves to prevent interruption ofthe circuit until a predetermined change in speed has taken place, andmeans whereby movement of said valve causes change of the speed at whichthe speed responsive means interrupts said circuit.

14. In combination, a prime mover, a valve means controlling theadmission of elastic fluid thereto, a motor for operating1 the valvemeans, means controlling the motor to effect movement of the valvemeans, said controlling means having two positions, one wherein iteffects movement of' the valve means toward open position and anotherwherein it effects movement of the valve means toward closed position,and mea-ns responsive to an operating condition of the p ime mover forperiodically moving said controlling` means from one of its positions tothe other.

15. In combination, a prime mover, a valve means controlling theadmission of elastic fluid thereto, a motor for operating the valvemeans, means controlling the motor to eil'ect movement of the valvemeans, said controlling means having two positions, one wherein iteffects movement of the valve means toward open position and anotherwherein it effects movement of the valve means toward closed position,and means responsive to the speed of the prime mover for periodicallymoving said controlling means from one of its positions to the other.

1G. In combination, a prime mover, a valve means controlling theadmission of elastic fluid thereto, a motor for operating the valvemeans, means controlling the motor to effect movement of the valvemeans, said controlling means having two positions, one wherein iteffects movement of the valve means toward open position and anotherwherein iteffects movement of the valve means toward closed position, anelectromagnet for moving said controlling means from one of itspositions to the other, an electric circuit for the eleetromagnet, andmeans responsive to an operating condition of the prime mover forperiodically opening and closing said electric circuit.

In witness whereof, I have hereunto set my hand this 7th day of May,1928.

WILLIAM L. R. EMMET.

